Reddit mentions of Stohlquist Men's Escape Personal Floatation Device, Yellow, X-Large/XX-Large

Obviously, it will depend on what he's already gotten for himself, what you can afford, what kind of sailing he's doing, and where you are.

You know your dad, I don't, but I'm going to suggest that a genuinely antique spyglass isn't going to have the utility you are envisioning. If he has a den/study/other area to display a curio, then fine, but it probably shouldn't be knocked around and soaked in the ways it will while sailing. A good [waterproof pair of binoculars] ( http://www.amazon.com/Bushnell-Waterproof-Fogproof-Prism-Binocular/dp/B006U3ZIWQ/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1370063798&sr=1-1&keywords=waterproof+binoculars) would be much better, IMO.

In my limited experience, here are some things most sailors might need, in no particular order:

• PFD--Personal Floatation Device, "lifejacket". On wetter, faster and/or smaller boats many people like a [kayak style vest] (http://www.amazon.com/Stohlquist-Personal-Floatation-X-Large-XX-Large/dp/B000FB9JBU/ref=sr_1_10?s=sporting-goods&ie=UTF8&qid=1370063280&sr=1-10&keywords=paddling+vest) . If it's a drier cruising style of sailing, [an automatic inflating vest] ( http://www.amazon.com/Revere-ComfortMax-Inflatable-Automatic-30-52-Inch/dp/B000EG3VI8/ref=sr_1_6?ie=UTF8&qid=1370063031&sr=8-6&keywords=automatic+inflatable+life+vest) is great. I linked an inflatable with a safety harness, a good idea for offshore, rough weather but if it's sunny-day and flat water sailing, then a sub-$100 version should be great.
  
  
• A hat they will wear. If you know him just right, you can pick out his "sailing hat" for life. Maybe a ball cap with the perfect logo on it, maybe a hiking/sun hat from the outdoor supplier, maybe a Tilley hat. It will live on the boat and he will wear it as soon as he steps on board.
  
  
• Gloves. Plenty to choose from. [Here's an avereage priced, commonly available sample] (http://www.amazon.com/Deckhand-Gloves-Deck-Glove-Short/dp/B00140P1DG/ref=sr_1_2?s=sporting-goods&ie=UTF8&qid=1370063702&sr=1-2&keywords=gill+deckhand)
  
  
• Footwear. Way too dependent on the type of sailing for me to supply good samples. Post specifics if you want suggestions, otherwise google "sailing boots(or shoes)" for ideas.
  
  
• Knife. Plenty of basic ["Sailing Knives"'] (http://www.amazon.com/Maxam-SKRULE-Misc-Sailors-Tool/dp/B003COEDMW/ref=sr_1_4?s=sporting-goods&ie=UTF8&qid=1370064431&sr=1-4&keywords=sailing+knife) on the market. Normally includes a blade (duh), a marlinspike and a shackle key. Again, you know him. Some prefer a [multitool with an easy to deploy blade] (http://www.amazon.com/Gerber-30-000587-Crucial-Multi-Tool-Black/dp/B00783N8MO/ref=sr_1_2?s=sporting-goods&ie=UTF8&qid=1370064557&sr=1-2&keywords=gerber+crucial), while still others will prefer a fixed, small (maybe 3 or 4 inches) blade with a sheath.
  
  
• Polarised sunglasses. 'nuff said
  
  
• Tethers (like "croakies") for abovementioned hats and glasses. It's windy, things prefer to fall overboard than stay attached to you.
  
  
• Foul weather gear. In some places, even when it's nice on land it is cold and wet on the water. You can use hiking style soft/hard shell jackets and rain gear as well as a VAST assortment of sailing-specific jackets and pants. Look at the apparel sections at websites like westmarine or mauiprosailing.
  
  
• Books. "Sail Trim" and "Knots" are good places to start. Normally, you should avoid a "for dummies" or "eyewitness" type book for someone who is already sailing.
  
  Does he own the boat? Jackpot! You almost cannot go wrong if you talk to him and do a little bit of research. ALL boats, huge or tiny, need many somethings, all the time, forever. Some silly expensive, others affordable. Charts, Compass, Air-horn, Fenders, Tail-bags, Sheets, Blocks, Cleats, Clutches, Etc., Etc.
  
  Oh, can't figure it all out? Try this:
  
  http://www.westmarine.com/webapp/wcs/stores/servlet/ShopView?langId=-1&storeId=11151&catalogId=10001&page=Gift-Cards&redirectTo=WM