As a general rule, you need to actually have a "sale" to incur a loss. Profits from the sale of almost all capital assets, with the exception of your principal residence, are subject to tax as a capital gain. Unfortunately, losses from the sale of most personal capital assets are not deductible.
Attached are two articles concerning sale of Personal Use Property;
http://www.taxplanningguide.ca/tax-planning-guide/section-2-individuals/selling-personal-use-capital...
https://turbotax.intuit.ca/tips/tax-tip-capital-gains-and-losses-on-the-sale-of-a-boat-6242
If you are in the business of buying and selling boats, you may be able to claim a loss when you actually sell a boat. And if this is the case, I would suggest seeking further advice from a qualified business advisor.
